The eastbound lanes of Highway 401 remain closed near Belleville as crews clean up after a collision involving at least 50 vehicles.
Ontario Provincial Police said the crash happened between County Road 30 in Brighton and County Road 40 in Trenton just minutes after midnight.
Approximately 40 tractor trailers and several smaller vehicles crashed due to poor driving conditions and icy roads, OPP said.
One of the tanker trucks was damaged in the crash, spilling lubricating oil onto the shoulder of the road.
Only four people were injured, and their injuries were not life-threatening.
The eastbound lanes of Hwy. 401 have been closed between County Road 30 and County Road 40 as crews clean debris and tow disabled vehicles. All westbound Hwy. 401 lanes have since been reopened.
The aftermath of a 50-vehicle collision is seen from the CTV News chopper near Belleville on Wednesday, March 18, 2015. (Jeff Long / CTV Toronto)